Effect of hopping rate and jump length of hopping electrons on the conductivity and dielectric properties of Co–Cd ferrite

• Published in: Journal of magnetism and magnetic materials Vol. 223; no. 2; pp. 127 - 132
• Main Authors: Hemeda, O.M., Barakat, M.M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.2001; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity phenomena in semiconductors and insulators; Dielectric constant; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Diffusion of vacancies; Electronic transport in condensed matter; Exact sciences and technology; Hopping rate; Mobility edges ; hopping transport; Permittivity (dielectric function); Physics; X-ray analysis; Dielectric constant; X-ray analysis; Hopping rate; Diffusion of vacancies; Cadmium oxides; Inorganic compounds; Electrical conductivity; Dielectric properties; Transition element compounds; Cobalt oxides; Hopping conductivity; Composition effect; Experimental study; Ferrites; Vacancy motion; Crystallographic site; Iron oxides; Quaternary compounds; Permittivity
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(00)00521-7

The cobalt cadmium ferrite has an n-type conductivity. As the Cd addition ( x) increases, the hopping rate increases and so the conductivity increases up to x=0.5. A sudden decrease in the hopping rate occurs above x=0.5 due to the decrease of Co 2+ ions on octahedral sites. Above x=0.7, the hopping rate increases again and the conductivity increases. As the hopping length increases the conductivity decreases, i.e. conductivity is inversely proportional to hopping length, but is directly proportional to the hopping rate of electrons. As the ferrous ions increase on octahedral sites, the conductivity increases and the jumping length decreases leading to the increase of dielectric constant.